Can microchannel reactors replace conventional kettle reactors for experiments?

With the concept of "micro-reaction", the microreactor has become a new type of means
that can replace the traditional kettle reactor for organic synthesis.

Microchannel reactor due to the miniaturization of the characteristic scale, heat transfer coefficient, mass transfer performance significantly enhanced, the conversion rate of the reaction, selectivity have been significantly improved, in addition to the fluid flow in the reactor uniform, the reaction process is continuous and controllable and the safety is high, so as to solve the problems often occur in the organic synthesis reaction in the traditional kettle reactor, such as poor mixing of the reaction material, uneven heat transfer, easy to occur side reactions and greater danger, etc.
Therefore, researchers have long been committed to the research and development of microreactors, and their application to various types of organic synthesis reactions
.

The specific surface area of the fluid in the microreactor can reach 104~106m2/m3, and the conventional reactor generally does not exceed 1000m2/m3, which is relatively high than that of conventional reactor by 1 to 3 orders of magnitude
.

Due to the reduction of the fluid thickness and the increase of the specific surface area, the reaction in the microchannel can be exchanged
with the wall.

In addition, the heat transfer coefficient of the microreactor is very large, and the heat transfer coefficient can reach 25kW/(m2· K)
。
Even if some chemical reactions with fast reaction rate and large heat release are carried out by the micro-reactor, the heat released by the reaction can be absorbed in time, and the reaction temperature fluctuation is small and stable, and the hot spot phenomenon
is avoided.

Therefore, for those near isothermal operations of strong exothermic reactions that cannot be effectively controlled in conventional reactors, they can be achieved in microchannel reactors, and the occurrence
of side reactions can be effectively inhibited.

The characteristic size of the microchannel reactor is much smaller than that of the conventional reactor, so that the physical quantities such as temperature and pressure in the microreactor are improved, that is, the driving force of material and energy transmission is improved, the driving force of mass transfer is increased, and the diffusion flux of volume and area is also expanded; The smaller scale of the microreactor reduces the diffusion distance and convection cycle of the fluid, reduces the mixing time of the liquid, and thus greatly enhances the mass transfer capacity
of the microreactor.